1. Field of the Invention
The present invention relates to a wireless communication system, and more particularly, to a method and apparatus for transmitting ACK/NACK for downlink transmission in a wireless communication system.
2. Discussion of the Related Art
In a wireless communication system, in order to determine whether data transmitted by a transmitter is successfully received by a receiver, the receiver may feed acknowledgement (ACK)/negative ACK (HACK) back to the transmitter. The transmitter performs an operation such as retransmission of previously transmitted data or transmission of new data based on the ACK/NACK feedback, thereby efficiently and accurately performing data transmission.
For example, in case of downlink transmission from a base station to a user equipment (UE), the UE which receives a physical downlink shared channel (PDSCH) in downlink subframe(s) may feed ACK/NACK information indicating whether or not the PDSCH is successfully received back to the base station after a predetermined time has elapsed, and the base station may receive the ACK/NACK information in one uplink subframe. In order to enable the base station to accurately receive the ACK/NACK information transmitted by the UE, resources used to transmit the ACK/NACK information in one uplink subframe need to be determined.